Burglar-alarm



A(Model.)

- R. MUENCH.

Burglar Alarm. N0. 240,838. Patented May 3, 18,181.

ww l I A INVENTLJR 77/(l/LOXLXl UNITED STATES PATENT Orricn.

ROBERT MUENCH, OF CHICAGO, ILLINOIS.

BURGLAR-ALARM.

SPECIFICATION, forming part of Letters Patent No. 240,838, dated May 3, 1881.

" Application filed January 8,1881. (Model.)

To all 'whom it may concern:

Be it known that I, ROBERT MUnNcH, of Chicago, in the county ot' Cook and State ot' Illinois, have invented certain new and useful Improvement in Burglar-Alarms, ot' which the following is a specification.

The object I have in view is to produce a simple and efficient alarm, which can be removably attached to a door, so that when the knob-spindle is turned the alarm will sound.

My invention consists in the peculiar devices and combinations of devices employed by me for that purpose, as fully hereinafter explained, and pointed out by the claims.

In the accompanying drawings, forming a part hereof, Figure 1 is a view of a portion of a door with my alarm attached; Fig. 2, an elevation of the alarm mechanism, the case and bell being in section; Fig. 3, a view of the mechanism with the bell removed and the case partly broken away; and Fig-4, a separate view of the pivoted dog.

Like letters denote corresponding parts in all the figures.

A is the case of the alarm, which is a spring-barrel inclosing a coiled spring, B, secured at its outer end to a stationary stud, and at its inner end to awinding-stem, a, projecting through the bottom of the case, and turned by a suitable handle, c. A large wheel, C, rests upon the spring, and turns loosely on the extended hub of a small ratchet, l), which has a square center, and turns with the square winding-stem a. A pawl, b, pressed forward by a spring, is pivoted to the wheel C, and engages with the ratchet D, so that the spring can be wound up without turning the wheel C. These parts are kept in position by the cover E of the spring-case, which is secured to the case by screws. The periphery of the wheel C is provided with beveled or ratchet teeth c.

A pawl, F, is pivoted to the cover E, and, working through a slot in the case, engages with the teeth c of the wheel C, holding such wheel until the pawl is withdrawn by the turning of the door-knob.

A dog, G, is pivoted at one end to the nnder side of the cover E within the case. This dog has one side, d, made of curved or hooked form, and the other side, Me, straight, or nearly so. Y

The wheel C has two sets ot' studs,fg, which engage with the opposite sides of the dog G. The studs j', preferably three in number, project from the web or spokes of the wheel, while the studs g are on the periphery oi the wheel, intermediate between the studs f. When the wheel C revolves, the studs f and g alternately strike the dog G and cause it to oscillate back and forth. The dog G is provided with a forked arm, It, which is offset from the dog, and works in a slot in the cover E.

The hammer-arm H is a spring-wire, which is coiled around a stud, ,011 the outside of the cover E, andthe other end of the wire engages with the forked arm hot' the dog G. I is screwed onto the end of an arm, k, carried by the cover E. The hammer vibrates within the bell, and strikes both sides ofthe same.

The case A is provided with ears Z, having locking-eyes m. These eyes are adapted to lock over the heads of screws n, (or hooks,) which are placed in the proper position for the alarm. i

A wire, o, is secured to the pawl F, and has a hooked outer end. When the alarm is attached to a door, as shown, the hooked end of the wire o will be connected with a loop, p, on the knob-spindle K. This will be done after the spring has been wound up and the. ears ot' the case have been attached to the screws n. Now, when the knob is turned to open the door, the pawl F will be withdrawn from the teeth of the wheel C, and such wheel being revolved by the spring the dog G will be vibrated and the alarm sounded..

During the day the alarm can be removed from position, if desired, and replaced at night.

The alarm could also be attached to a window-casing, and be connected with the sash, so that the raising ot' the sash will release the alarm.

What I claim as my invention isl. In a burglar-alarm, the combination, with the bell and hammer, of the `wheel C, connected with the spring by a pawl and ratchet, and having studs f g, and the pivo'ted dog G,

The bell vibrated by such studs, and connected with the pawl b, the pivoted dog G, and. the lockthe hammer-arm, substantially as described ing-paWIF, substantially as described and and shown. shown.

2. In aburglar-alarm, the combination` with ROBERT MUENGH. 5 the bell and hammer, 0f the spring B, the -Winding-spindle a, the Whee1C,ha,ving' ratchet-teeth c and studs f g, the ratchet-wheel D7 Witnesses:

OLIVER W. MARBLE, F. W. KASEHAGEN. 

